Basic thermodynamics Definition and 29 Threads

https://www.physicsforums.com/threads/confusion-over-intensive-properties-thermo.585648/post-3809940 Can someone explain this explanation given by Rap. Its an old thread so i cannot comment and ask him directly that is if he's still around.

I eat eggs, ham, peppers, and a pancake for breakfast. I cook the ham and peppers at the same time. For purposes of this question, I have the eggs and the pancake figured out. Given a gas stove, a small, nonstick aluminum frying pan (with lid) and corn oil; If my goals are (in order of...

Homework Statement Unit mass of a fluid at a pressure of 3 bar, and with a specific volume of 0.18 m^3/kg, contained in a cylinder fitted with a piston expands reversibly to a pressure of 0.6 bar according to the law p = c/v^2 , where c is a constant. Calculate the work done during the...

Homework Statement A mug containing a volume of ta initially at 90oC is in thermal contact with the enivronment at 20oC. Density of tea = ##10^{3}kgm^{-3}## Constant pressure specific heat capacity of tea: ##4.20 \times 10^{3} Jkg^{-1}K^{-1}## ... b) After reaching equilibrium, 0.01 J of...

Homework Statement http://i.imgur.com/jmLqca9.jpg pic of question Homework Equations W = p x dV, Q = dU + W etc The Attempt at a Solution I know what the different stages are, a-b and c-d are isobaric, d-a and b-c are isochoric and I believe the answer to a, the net work done in one cycle...

I've just transferred to a new university where they did certain aspects of thermodynamics in their first year, which is a problem because I didn't do any in my first year at the university I was previously at. I did some bits in high school but not to a very high level, so I understand the...

Hello there, Firstly I would like to welcome myself to the forum, my name is Ben and I'm 21 and I'm from the Isle of Mull off the west coast of Scotland. I am studying mechanical engineering and this question has been giving me a massive headache. If I have 60m3 of water at 60oC in a tank...

Homework Statement In Herbert Callen's text 'Thermodynamics and an introduction to thermostatistics', 2nd edition, Problem 1.10-1 on page 32 presents ten potential fundamental equations of thermo systems, labelled (a) - (j), and asks the reader to identify the five that are invalid because they...

Homework Statement Hi, I'm a new user and got this problem. Sorry to bother, but I couldn't find any relevant information from my Physics books.. The problem states: Build a heat engine using these processes: adiabatic, isothermal, isochoric and isothermal. The work-cycle of the engine must...

Given a system with known materials of known geometries, and an initial temperature profile, it seems relatively straight forward to calculate a final temperature profile. I assume there are computers that can do this for all kinds of arbitrary systems. What about determining the temperatures...

Dear Physics People, I am a religion teacher with a background in philosophy and theology. I haven't taken a physics or calculus in some years, so there is a lot of information that I'm missing in my head. So here's the deal. Airlines spend millions of dollars on fuel a day (around $32...

Homework Statement So we are given an insulating container with two compartments between which, heat can flow. In the left one, there exists m_1 of water at temp T_1 and on the right there exists m_2 of ice at temp T_2. What is the final composition and temperature? Homework Equations...

Homework Statement A sphere of radius .5m, temperature of 27 deg C, and emissivity = .85 is located in an environment of temperature 77 deg C. At what rate does the sphere (a)emit and (b)absorb thermal radiation? (c)What's the sphere's net rate of energy exchange? Homework Equations...

To increase the temperature of a vessel with 1 K the amount of 50 J energy must be supplied. In the vessel 250 g of a liquid is added. With a heating spiral, which develops 15 W, the temperature is increased. Eventually it is stabilized and becomes constant until the heat supply gets turned off...

Homework Statement What is the ΔU° at 25°C for the following reaction at constant pressure: C_{2}H_{2} (g) + 5/2O_{2} (g) \rightarrow 2CO_{2} (g) + H_{2}O (g) ΔH° = -1299.5kJ Homework Equations ΔU = Q ± W PV = nRT W = PΔV The Attempt at a Solution Since we have constant pressure, ΔH° =...

Homework Statement Okay, so the problem given is that there is a rigid tank with a partition down the middle. For partition A, the specific volume, the temperature, and therefore the pressure is known. The mass, or total volume is not known. Partition B is a vacuum for which the total volume is...

Homework Statement A fixed mass of an ideal gas undergoes a cycle PQRP of changes as shown in the following figure: Some energy changes during the cycle PQRP are shown in the following figure Complete the Figure Homework Equations Find the work done on gas from R to P The Attempt at a...

I plan on adding a 5th class to my semester (which is already quite packed), however I was wondering if this sounded like the Thermodynamics class that everyone on PF always complains about: "ENGR 251 Thermodynamics I (3 credits) Prerequisite: MATH 203 (Cegep Mathematics 103 [Calculus 1])...

I want to heat a small reservoir filled with water. I want to find out how long it will take to heat the water from a specific temperature to a specific temperature. random example. The continuous power source is 720 watts The Initial temp is -40c The Final temp is 70c No heat loss. Water...

How to prove that (a)(dU/dV)T=0 (b)(dH/dP)T=0 for an ideal gas. Where U is internal energy per unit mass, V is volume, T is temperature (which is held constant for above 2 question), H is the enthalpy per unit mass, and P is the pressure. I found this in a thermodynamics textbook. This is...

For an ideal gas, how to prove that: (a) its internal energy does not change with volume at constant temperature (b) its enthalpy does not change with pressure at constant temperature Thanks.

Homework Statement A 50.0g copper calorimeter contains 250 g of water at 20 C. how much steam must be condensed into the water if the final temperature of the system is to reach 50 C? Homework Equations Q=-mLv where Q is heat energy, m is mass, Lv is latent vaporization constant of water...

Homework Statement http://imgur.com/44ay2.png" Homework Equations Below. The Attempt at a Solution A. W=Fd 2000N x 0.001m = 2J B. This is where I am stuck. Can I assume that the pressure doesn't change when it is pushed in because it says that it is pushed in "suddenly"...

Homework Statement 0.025kg of steam at a quality of 10% and a pressure of 2 bar is heated in a rigid container until the temperature reaches 200 degrees celcius. find the final quality (x). Homework Equations The Attempt at a Solution ok, so i use the steam tables and find vf and...

Homework Statement The energy of a particular system,of one mole, is given by: U = AP^2 V (A) where A is a positive constant of units [P^(-1)]. Find the equation of the adiabat in the P-V plane Homework Equations I guess dQ = 0 (1) and dU + PdV= 0 (2) The Attempt at a Solution...

Please help! I need these done by wednesday and for the life of me i cannot seem to get the correct answer. Homework Statement How much ice must melt at 0 deg. C to gain 5 g of mass? Homework Equations I cannot seem to find many equations that relate thermodynamics and mass, maybe...

Ive just started thermo after being out of the physics game for awhile. The professor is less than stellar and bascially we have to learn out of the book. The problem is easy, I know, but I just can't figure it out. Its as follows: Cylinder containing gas has piston with cross-sectional area...

Hello everyone first time posting here. I have a thermodynamics question that my teacher told me should be really easy. But I am having a lot of difficulty on it. Any help would be appreciated. For question 2 by simplying plugging in the information given I am able to get the energy of...

My teacher was telling me how when you pour a hot liquid into a crystal glass that it will shatter. This is due to the transfer of heat, which speeds up the molecules in the cup. But air had something to do with it and I can not remember what. Does anyone have an idea? Thanks.